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| author | Alan Stern <stern@rowland.harvard.edu> | 2010-03-06 15:04:03 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:52:29 -0700 |
| commit | aaaa549b386fdd80b93b447541f42b313b103f95 (patch) | |
| tree | a3dfc8a690a4e558a0adca9094f807e7bca5db4e | |
| parent | e3dc90e7cd7328ffae169ba41500d50aa1c893d3 (diff) | |
| download | lwn-aaaa549b386fdd80b93b447541f42b313b103f95.tar.gz lwn-aaaa549b386fdd80b93b447541f42b313b103f95.zip | |
USB: fix usbfs regression
commit 7152b592593b9d48b33f8997b1dfd6df9143f7ec upstream.
This patch (as1352) fixes a bug in the way isochronous input data is
returned to userspace for usbfs transfers. The entire buffer must be
copied, not just the first actual_length bytes, because the individual
packets will be discontiguous if any of them are short.
Reported-by: Markus Rechberger <mrechberger@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/usb/core/devio.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 1902694f6eb8..8657266f268b 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1123,6 +1123,13 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb, free_async(as); return -ENOMEM; } + /* Isochronous input data may end up being discontiguous + * if some of the packets are short. Clear the buffer so + * that the gaps don't leak kernel data to userspace. + */ + if (is_in && uurb->type == USBDEVFS_URB_TYPE_ISO) + memset(as->urb->transfer_buffer, 0, + uurb->buffer_length); } as->urb->dev = ps->dev; as->urb->pipe = (uurb->type << 30) | @@ -1224,10 +1231,14 @@ static int processcompl(struct async *as, void __user * __user *arg) void __user *addr = as->userurb; unsigned int i; - if (as->userbuffer && urb->actual_length) - if (copy_to_user(as->userbuffer, urb->transfer_buffer, - urb->actual_length)) + if (as->userbuffer && urb->actual_length) { + if (urb->number_of_packets > 0) /* Isochronous */ + i = urb->transfer_buffer_length; + else /* Non-Isoc */ + i = urb->actual_length; + if (copy_to_user(as->userbuffer, urb->transfer_buffer, i)) goto err_out; + } if (put_user(as->status, &userurb->status)) goto err_out; if (put_user(urb->actual_length, &userurb->actual_length)) |